| 1 | /* |
| 2 | * Copyright (c) 1985, Avadis Tevanian, Jr., Michael Wayne Young |
| 3 | * Copyright (c) 1987 Carnegie-Mellon University |
| 4 | * Copyright (c) 1991 Regents of the University of California. |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * This code is derived from software contributed to Berkeley by |
| 8 | * The Mach Operating System project at Carnegie-Mellon University. |
| 9 | * |
| 10 | * The CMU software License Agreement specifies the terms and conditions |
| 11 | * for use and redistribution. |
| 12 | * |
| 13 | * @(#)vm_map.c 7.1 (Berkeley) %G% |
| 14 | */ |
| 15 | |
| 16 | /* |
| 17 | * Virtual memory mapping module. |
| 18 | */ |
| 19 | |
| 20 | #include "types.h" |
| 21 | #include "malloc.h" |
| 22 | #include "../vm/vm_param.h" |
| 23 | #include "../vm/vm_map.h" |
| 24 | #include "../vm/vm_page.h" |
| 25 | #include "../vm/vm_object.h" |
| 26 | |
| 27 | /* |
| 28 | * Virtual memory maps provide for the mapping, protection, |
| 29 | * and sharing of virtual memory objects. In addition, |
| 30 | * this module provides for an efficient virtual copy of |
| 31 | * memory from one map to another. |
| 32 | * |
| 33 | * Synchronization is required prior to most operations. |
| 34 | * |
| 35 | * Maps consist of an ordered doubly-linked list of simple |
| 36 | * entries; a single hint is used to speed up lookups. |
| 37 | * |
| 38 | * In order to properly represent the sharing of virtual |
| 39 | * memory regions among maps, the map structure is bi-level. |
| 40 | * Top-level ("address") maps refer to regions of sharable |
| 41 | * virtual memory. These regions are implemented as |
| 42 | * ("sharing") maps, which then refer to the actual virtual |
| 43 | * memory objects. When two address maps "share" memory, |
| 44 | * their top-level maps both have references to the same |
| 45 | * sharing map. When memory is virtual-copied from one |
| 46 | * address map to another, the references in the sharing |
| 47 | * maps are actually copied -- no copying occurs at the |
| 48 | * virtual memory object level. |
| 49 | * |
| 50 | * Since portions of maps are specified by start/end addreses, |
| 51 | * which may not align with existing map entries, all |
| 52 | * routines merely "clip" entries to these start/end values. |
| 53 | * [That is, an entry is split into two, bordering at a |
| 54 | * start or end value.] Note that these clippings may not |
| 55 | * always be necessary (as the two resulting entries are then |
| 56 | * not changed); however, the clipping is done for convenience. |
| 57 | * No attempt is currently made to "glue back together" two |
| 58 | * abutting entries. |
| 59 | * |
| 60 | * As mentioned above, virtual copy operations are performed |
| 61 | * by copying VM object references from one sharing map to |
| 62 | * another, and then marking both regions as copy-on-write. |
| 63 | * It is important to note that only one writeable reference |
| 64 | * to a VM object region exists in any map -- this means that |
| 65 | * shadow object creation can be delayed until a write operation |
| 66 | * occurs. |
| 67 | */ |
| 68 | |
| 69 | /* |
| 70 | * vm_map_init: |
| 71 | * |
| 72 | * Initialize the vm_map module. Must be called before |
| 73 | * any other vm_map routines. |
| 74 | * |
| 75 | * Map and entry structures are allocated from the general |
| 76 | * purpose memory pool with some exceptions: |
| 77 | * |
| 78 | * - The kernel map and kmem submap are allocated statically. |
| 79 | * - Kernel map entries are allocated out of a static pool. |
| 80 | * |
| 81 | * These restrictions are necessary since malloc() uses the |
| 82 | * maps and requires map entries. |
| 83 | */ |
| 84 | |
| 85 | vm_offset_t kentry_data; |
| 86 | vm_size_t kentry_data_size; |
| 87 | vm_map_entry_t kentry_free; |
| 88 | vm_map_t kmap_free; |
| 89 | |
| 90 | void vm_map_init() |
| 91 | { |
| 92 | register int i; |
| 93 | register vm_map_entry_t mep; |
| 94 | vm_map_t mp; |
| 95 | |
| 96 | /* |
| 97 | * Static map structures for allocation before initialization of |
| 98 | * kernel map or kmem map. vm_map_create knows how to deal with them. |
| 99 | */ |
| 100 | kmap_free = mp = (vm_map_t) kentry_data; |
| 101 | i = MAX_KMAP; |
| 102 | while (--i > 0) { |
| 103 | mp->header.next = (vm_map_entry_t) (mp + 1); |
| 104 | mp++; |
| 105 | } |
| 106 | mp++->header.next = VM_MAP_ENTRY_NULL; |
| 107 | |
| 108 | /* |
| 109 | * Form a free list of statically allocated kernel map entries |
| 110 | * with the rest. |
| 111 | */ |
| 112 | kentry_free = mep = (vm_map_entry_t) mp; |
| 113 | i = (kentry_data_size - MAX_KMAP * sizeof *mp) / sizeof *mep; |
| 114 | while (--i > 0) { |
| 115 | mep->next = mep + 1; |
| 116 | mep++; |
| 117 | } |
| 118 | mep->next = VM_MAP_ENTRY_NULL; |
| 119 | } |
| 120 | |
| 121 | /* |
| 122 | * vm_map_create: |
| 123 | * |
| 124 | * Creates and returns a new empty VM map with |
| 125 | * the given physical map structure, and having |
| 126 | * the given lower and upper address bounds. |
| 127 | */ |
| 128 | vm_map_t vm_map_create(pmap, min, max, pageable) |
| 129 | pmap_t pmap; |
| 130 | vm_offset_t min, max; |
| 131 | boolean_t pageable; |
| 132 | { |
| 133 | register vm_map_t result; |
| 134 | extern vm_map_t kernel_map, kmem_map; |
| 135 | |
| 136 | if (kmem_map == VM_MAP_NULL) { |
| 137 | result = kmap_free; |
| 138 | kmap_free = (vm_map_t) result->header.next; |
| 139 | } else |
| 140 | MALLOC(result, vm_map_t, sizeof(struct vm_map), |
| 141 | M_VMMAP, M_WAITOK); |
| 142 | |
| 143 | if (result == VM_MAP_NULL) |
| 144 | panic("vm_map_create: out of maps"); |
| 145 | |
| 146 | result->header.next = result->header.prev = &result->header; |
| 147 | result->nentries = 0; |
| 148 | result->size = 0; |
| 149 | result->ref_count = 1; |
| 150 | result->pmap = pmap; |
| 151 | result->is_main_map = TRUE; |
| 152 | result->min_offset = min; |
| 153 | result->max_offset = max; |
| 154 | result->entries_pageable = pageable; |
| 155 | result->first_free = &result->header; |
| 156 | result->hint = &result->header; |
| 157 | result->timestamp = 0; |
| 158 | lock_init(&result->lock, TRUE); |
| 159 | simple_lock_init(&result->ref_lock); |
| 160 | simple_lock_init(&result->hint_lock); |
| 161 | return(result); |
| 162 | } |
| 163 | |
| 164 | /* |
| 165 | * vm_map_entry_create: [ internal use only ] |
| 166 | * |
| 167 | * Allocates a VM map entry for insertion. |
| 168 | * No entry fields are filled in. This routine is |
| 169 | */ |
| 170 | vm_map_entry_t vm_map_entry_create(map) |
| 171 | vm_map_t map; |
| 172 | { |
| 173 | vm_map_entry_t entry; |
| 174 | extern vm_map_t kernel_map, kmem_map, mb_map; |
| 175 | |
| 176 | if (map == kernel_map || map == kmem_map || map == mb_map) { |
| 177 | if (entry = kentry_free) |
| 178 | kentry_free = kentry_free->next; |
| 179 | } else |
| 180 | MALLOC(entry, vm_map_entry_t, sizeof(struct vm_map_entry), |
| 181 | M_VMMAPENT, M_WAITOK); |
| 182 | if (entry == VM_MAP_ENTRY_NULL) |
| 183 | panic("vm_map_entry_create: out of map entries"); |
| 184 | |
| 185 | return(entry); |
| 186 | } |
| 187 | |
| 188 | /* |
| 189 | * vm_map_entry_dispose: [ internal use only ] |
| 190 | * |
| 191 | * Inverse of vm_map_entry_create. |
| 192 | */ |
| 193 | void vm_map_entry_dispose(map, entry) |
| 194 | vm_map_t map; |
| 195 | vm_map_entry_t entry; |
| 196 | { |
| 197 | extern vm_map_t kernel_map, kmem_map, mb_map; |
| 198 | |
| 199 | if (map == kernel_map || map == kmem_map || map == mb_map) { |
| 200 | entry->next = kentry_free; |
| 201 | kentry_free = entry; |
| 202 | } else |
| 203 | FREE(entry, M_VMMAPENT); |
| 204 | } |
| 205 | |
| 206 | /* |
| 207 | * vm_map_entry_{un,}link: |
| 208 | * |
| 209 | * Insert/remove entries from maps. |
| 210 | */ |
| 211 | #define vm_map_entry_link(map, after_where, entry) \ |
| 212 | { \ |
| 213 | (map)->nentries++; \ |
| 214 | (entry)->prev = (after_where); \ |
| 215 | (entry)->next = (after_where)->next; \ |
| 216 | (entry)->prev->next = (entry); \ |
| 217 | (entry)->next->prev = (entry); \ |
| 218 | } |
| 219 | #define vm_map_entry_unlink(map, entry) \ |
| 220 | { \ |
| 221 | (map)->nentries--; \ |
| 222 | (entry)->next->prev = (entry)->prev; \ |
| 223 | (entry)->prev->next = (entry)->next; \ |
| 224 | } |
| 225 | |
| 226 | /* |
| 227 | * vm_map_reference: |
| 228 | * |
| 229 | * Creates another valid reference to the given map. |
| 230 | * |
| 231 | */ |
| 232 | void vm_map_reference(map) |
| 233 | register vm_map_t map; |
| 234 | { |
| 235 | if (map == VM_MAP_NULL) |
| 236 | return; |
| 237 | |
| 238 | simple_lock(&map->ref_lock); |
| 239 | map->ref_count++; |
| 240 | simple_unlock(&map->ref_lock); |
| 241 | } |
| 242 | |
| 243 | /* |
| 244 | * vm_map_deallocate: |
| 245 | * |
| 246 | * Removes a reference from the specified map, |
| 247 | * destroying it if no references remain. |
| 248 | * The map should not be locked. |
| 249 | */ |
| 250 | void vm_map_deallocate(map) |
| 251 | register vm_map_t map; |
| 252 | { |
| 253 | register int c; |
| 254 | |
| 255 | if (map == VM_MAP_NULL) |
| 256 | return; |
| 257 | |
| 258 | simple_lock(&map->ref_lock); |
| 259 | c = --map->ref_count; |
| 260 | simple_unlock(&map->ref_lock); |
| 261 | |
| 262 | if (c > 0) { |
| 263 | return; |
| 264 | } |
| 265 | |
| 266 | /* |
| 267 | * Lock the map, to wait out all other references |
| 268 | * to it. |
| 269 | */ |
| 270 | |
| 271 | vm_map_lock(map); |
| 272 | |
| 273 | (void) vm_map_delete(map, map->min_offset, map->max_offset); |
| 274 | |
| 275 | pmap_destroy(map->pmap); |
| 276 | |
| 277 | FREE(map, M_VMMAP); |
| 278 | } |
| 279 | |
| 280 | /* |
| 281 | * vm_map_insert: [ internal use only ] |
| 282 | * |
| 283 | * Inserts the given whole VM object into the target |
| 284 | * map at the specified address range. The object's |
| 285 | * size should match that of the address range. |
| 286 | * |
| 287 | * Requires that the map be locked, and leaves it so. |
| 288 | */ |
| 289 | vm_map_insert(map, object, offset, start, end) |
| 290 | vm_map_t map; |
| 291 | vm_object_t object; |
| 292 | vm_offset_t offset; |
| 293 | vm_offset_t start; |
| 294 | vm_offset_t end; |
| 295 | { |
| 296 | register vm_map_entry_t new_entry; |
| 297 | register vm_map_entry_t prev_entry; |
| 298 | vm_map_entry_t temp_entry; |
| 299 | |
| 300 | /* |
| 301 | * Check that the start and end points are not bogus. |
| 302 | */ |
| 303 | |
| 304 | if ((start < map->min_offset) || (end > map->max_offset) || |
| 305 | (start >= end)) |
| 306 | return(KERN_INVALID_ADDRESS); |
| 307 | |
| 308 | /* |
| 309 | * Find the entry prior to the proposed |
| 310 | * starting address; if it's part of an |
| 311 | * existing entry, this range is bogus. |
| 312 | */ |
| 313 | |
| 314 | if (vm_map_lookup_entry(map, start, &temp_entry)) |
| 315 | return(KERN_NO_SPACE); |
| 316 | |
| 317 | prev_entry = temp_entry; |
| 318 | |
| 319 | /* |
| 320 | * Assert that the next entry doesn't overlap the |
| 321 | * end point. |
| 322 | */ |
| 323 | |
| 324 | if ((prev_entry->next != &map->header) && |
| 325 | (prev_entry->next->start < end)) |
| 326 | return(KERN_NO_SPACE); |
| 327 | |
| 328 | /* |
| 329 | * See if we can avoid creating a new entry by |
| 330 | * extending one of our neighbors. |
| 331 | */ |
| 332 | |
| 333 | if (object == VM_OBJECT_NULL) { |
| 334 | if ((prev_entry != &map->header) && |
| 335 | (prev_entry->end == start) && |
| 336 | (map->is_main_map) && |
| 337 | (prev_entry->is_a_map == FALSE) && |
| 338 | (prev_entry->is_sub_map == FALSE) && |
| 339 | (prev_entry->inheritance == VM_INHERIT_DEFAULT) && |
| 340 | (prev_entry->protection == VM_PROT_DEFAULT) && |
| 341 | (prev_entry->max_protection == VM_PROT_DEFAULT) && |
| 342 | (prev_entry->wired_count == 0)) { |
| 343 | |
| 344 | if (vm_object_coalesce(prev_entry->object.vm_object, |
| 345 | VM_OBJECT_NULL, |
| 346 | prev_entry->offset, |
| 347 | (vm_offset_t) 0, |
| 348 | (vm_size_t)(prev_entry->end |
| 349 | - prev_entry->start), |
| 350 | (vm_size_t)(end - prev_entry->end))) { |
| 351 | /* |
| 352 | * Coalesced the two objects - can extend |
| 353 | * the previous map entry to include the |
| 354 | * new range. |
| 355 | */ |
| 356 | map->size += (end - prev_entry->end); |
| 357 | prev_entry->end = end; |
| 358 | return(KERN_SUCCESS); |
| 359 | } |
| 360 | } |
| 361 | } |
| 362 | |
| 363 | /* |
| 364 | * Create a new entry |
| 365 | */ |
| 366 | |
| 367 | new_entry = vm_map_entry_create(map); |
| 368 | new_entry->start = start; |
| 369 | new_entry->end = end; |
| 370 | |
| 371 | new_entry->is_a_map = FALSE; |
| 372 | new_entry->is_sub_map = FALSE; |
| 373 | new_entry->object.vm_object = object; |
| 374 | new_entry->offset = offset; |
| 375 | |
| 376 | new_entry->copy_on_write = FALSE; |
| 377 | new_entry->needs_copy = FALSE; |
| 378 | |
| 379 | if (map->is_main_map) { |
| 380 | new_entry->inheritance = VM_INHERIT_DEFAULT; |
| 381 | new_entry->protection = VM_PROT_DEFAULT; |
| 382 | new_entry->max_protection = VM_PROT_DEFAULT; |
| 383 | new_entry->wired_count = 0; |
| 384 | } |
| 385 | |
| 386 | /* |
| 387 | * Insert the new entry into the list |
| 388 | */ |
| 389 | |
| 390 | vm_map_entry_link(map, prev_entry, new_entry); |
| 391 | map->size += new_entry->end - new_entry->start; |
| 392 | |
| 393 | /* |
| 394 | * Update the free space hint |
| 395 | */ |
| 396 | |
| 397 | if ((map->first_free == prev_entry) && (prev_entry->end >= new_entry->start)) |
| 398 | map->first_free = new_entry; |
| 399 | |
| 400 | return(KERN_SUCCESS); |
| 401 | } |
| 402 | |
| 403 | /* |
| 404 | * SAVE_HINT: |
| 405 | * |
| 406 | * Saves the specified entry as the hint for |
| 407 | * future lookups. Performs necessary interlocks. |
| 408 | */ |
| 409 | #define SAVE_HINT(map,value) \ |
| 410 | simple_lock(&(map)->hint_lock); \ |
| 411 | (map)->hint = (value); \ |
| 412 | simple_unlock(&(map)->hint_lock); |
| 413 | |
| 414 | /* |
| 415 | * vm_map_lookup_entry: [ internal use only ] |
| 416 | * |
| 417 | * Finds the map entry containing (or |
| 418 | * immediately preceding) the specified address |
| 419 | * in the given map; the entry is returned |
| 420 | * in the "entry" parameter. The boolean |
| 421 | * result indicates whether the address is |
| 422 | * actually contained in the map. |
| 423 | */ |
| 424 | boolean_t vm_map_lookup_entry(map, address, entry) |
| 425 | register vm_map_t map; |
| 426 | register vm_offset_t address; |
| 427 | vm_map_entry_t *entry; /* OUT */ |
| 428 | { |
| 429 | register vm_map_entry_t cur; |
| 430 | register vm_map_entry_t last; |
| 431 | |
| 432 | /* |
| 433 | * Start looking either from the head of the |
| 434 | * list, or from the hint. |
| 435 | */ |
| 436 | |
| 437 | simple_lock(&map->hint_lock); |
| 438 | cur = map->hint; |
| 439 | simple_unlock(&map->hint_lock); |
| 440 | |
| 441 | if (cur == &map->header) |
| 442 | cur = cur->next; |
| 443 | |
| 444 | if (address >= cur->start) { |
| 445 | /* |
| 446 | * Go from hint to end of list. |
| 447 | * |
| 448 | * But first, make a quick check to see if |
| 449 | * we are already looking at the entry we |
| 450 | * want (which is usually the case). |
| 451 | * Note also that we don't need to save the hint |
| 452 | * here... it is the same hint (unless we are |
| 453 | * at the header, in which case the hint didn't |
| 454 | * buy us anything anyway). |
| 455 | */ |
| 456 | last = &map->header; |
| 457 | if ((cur != last) && (cur->end > address)) { |
| 458 | *entry = cur; |
| 459 | return(TRUE); |
| 460 | } |
| 461 | } |
| 462 | else { |
| 463 | /* |
| 464 | * Go from start to hint, *inclusively* |
| 465 | */ |
| 466 | last = cur->next; |
| 467 | cur = map->header.next; |
| 468 | } |
| 469 | |
| 470 | /* |
| 471 | * Search linearly |
| 472 | */ |
| 473 | |
| 474 | while (cur != last) { |
| 475 | if (cur->end > address) { |
| 476 | if (address >= cur->start) { |
| 477 | /* |
| 478 | * Save this lookup for future |
| 479 | * hints, and return |
| 480 | */ |
| 481 | |
| 482 | *entry = cur; |
| 483 | SAVE_HINT(map, cur); |
| 484 | return(TRUE); |
| 485 | } |
| 486 | break; |
| 487 | } |
| 488 | cur = cur->next; |
| 489 | } |
| 490 | *entry = cur->prev; |
| 491 | SAVE_HINT(map, *entry); |
| 492 | return(FALSE); |
| 493 | } |
| 494 | |
| 495 | /* |
| 496 | * vm_map_find finds an unallocated region in the target address |
| 497 | * map with the given length. The search is defined to be |
| 498 | * first-fit from the specified address; the region found is |
| 499 | * returned in the same parameter. |
| 500 | * |
| 501 | */ |
| 502 | vm_map_find(map, object, offset, addr, length, find_space) |
| 503 | vm_map_t map; |
| 504 | vm_object_t object; |
| 505 | vm_offset_t offset; |
| 506 | vm_offset_t *addr; /* IN/OUT */ |
| 507 | vm_size_t length; |
| 508 | boolean_t find_space; |
| 509 | { |
| 510 | register vm_map_entry_t entry; |
| 511 | register vm_offset_t start; |
| 512 | register vm_offset_t end; |
| 513 | int result; |
| 514 | |
| 515 | start = *addr; |
| 516 | |
| 517 | vm_map_lock(map); |
| 518 | |
| 519 | if (find_space) { |
| 520 | /* |
| 521 | * Calculate the first possible address. |
| 522 | */ |
| 523 | |
| 524 | if (start < map->min_offset) |
| 525 | start = map->min_offset; |
| 526 | if (start > map->max_offset) { |
| 527 | vm_map_unlock(map); |
| 528 | return (KERN_NO_SPACE); |
| 529 | } |
| 530 | |
| 531 | /* |
| 532 | * Look for the first possible address; |
| 533 | * if there's already something at this |
| 534 | * address, we have to start after it. |
| 535 | */ |
| 536 | |
| 537 | if (start == map->min_offset) { |
| 538 | if ((entry = map->first_free) != &map->header) |
| 539 | start = entry->end; |
| 540 | } else { |
| 541 | vm_map_entry_t tmp_entry; |
| 542 | if (vm_map_lookup_entry(map, start, &tmp_entry)) |
| 543 | start = tmp_entry->end; |
| 544 | entry = tmp_entry; |
| 545 | } |
| 546 | |
| 547 | /* |
| 548 | * In any case, the "entry" always precedes |
| 549 | * the proposed new region throughout the |
| 550 | * loop: |
| 551 | */ |
| 552 | |
| 553 | while (TRUE) { |
| 554 | register vm_map_entry_t next; |
| 555 | |
| 556 | /* |
| 557 | * Find the end of the proposed new region. |
| 558 | * Be sure we didn't go beyond the end, or |
| 559 | * wrap around the address. |
| 560 | */ |
| 561 | |
| 562 | end = start + length; |
| 563 | |
| 564 | if ((end > map->max_offset) || (end < start)) { |
| 565 | vm_map_unlock(map); |
| 566 | return (KERN_NO_SPACE); |
| 567 | } |
| 568 | |
| 569 | /* |
| 570 | * If there are no more entries, we must win. |
| 571 | */ |
| 572 | |
| 573 | next = entry->next; |
| 574 | if (next == &map->header) |
| 575 | break; |
| 576 | |
| 577 | /* |
| 578 | * If there is another entry, it must be |
| 579 | * after the end of the potential new region. |
| 580 | */ |
| 581 | |
| 582 | if (next->start >= end) |
| 583 | break; |
| 584 | |
| 585 | /* |
| 586 | * Didn't fit -- move to the next entry. |
| 587 | */ |
| 588 | |
| 589 | entry = next; |
| 590 | start = entry->end; |
| 591 | } |
| 592 | *addr = start; |
| 593 | |
| 594 | SAVE_HINT(map, entry); |
| 595 | } |
| 596 | |
| 597 | result = vm_map_insert(map, object, offset, start, start + length); |
| 598 | |
| 599 | vm_map_unlock(map); |
| 600 | return(result); |
| 601 | } |
| 602 | |
| 603 | /* |
| 604 | * vm_map_simplify_entry: [ internal use only ] |
| 605 | * |
| 606 | * Simplify the given map entry by: |
| 607 | * removing extra sharing maps |
| 608 | * [XXX maybe later] merging with a neighbor |
| 609 | */ |
| 610 | void vm_map_simplify_entry(map, entry) |
| 611 | vm_map_t map; |
| 612 | vm_map_entry_t entry; |
| 613 | { |
| 614 | #ifdef lint |
| 615 | map++; |
| 616 | #endif lint |
| 617 | |
| 618 | /* |
| 619 | * If this entry corresponds to a sharing map, then |
| 620 | * see if we can remove the level of indirection. |
| 621 | * If it's not a sharing map, then it points to |
| 622 | * a VM object, so see if we can merge with either |
| 623 | * of our neighbors. |
| 624 | */ |
| 625 | |
| 626 | if (entry->is_sub_map) |
| 627 | return; |
| 628 | if (entry->is_a_map) { |
| 629 | #if 0 |
| 630 | vm_map_t my_share_map; |
| 631 | int count; |
| 632 | |
| 633 | my_share_map = entry->object.share_map; |
| 634 | simple_lock(&my_share_map->ref_lock); |
| 635 | count = my_share_map->ref_count; |
| 636 | simple_unlock(&my_share_map->ref_lock); |
| 637 | |
| 638 | if (count == 1) { |
| 639 | /* Can move the region from |
| 640 | * entry->start to entry->end (+ entry->offset) |
| 641 | * in my_share_map into place of entry. |
| 642 | * Later. |
| 643 | */ |
| 644 | } |
| 645 | #endif 0 |
| 646 | } |
| 647 | else { |
| 648 | /* |
| 649 | * Try to merge with our neighbors. |
| 650 | * |
| 651 | * Conditions for merge are: |
| 652 | * |
| 653 | * 1. entries are adjacent. |
| 654 | * 2. both entries point to objects |
| 655 | * with null pagers. |
| 656 | * |
| 657 | * If a merge is possible, we replace the two |
| 658 | * entries with a single entry, then merge |
| 659 | * the two objects into a single object. |
| 660 | * |
| 661 | * Now, all that is left to do is write the |
| 662 | * code! |
| 663 | */ |
| 664 | } |
| 665 | } |
| 666 | |
| 667 | /* |
| 668 | * vm_map_clip_start: [ internal use only ] |
| 669 | * |
| 670 | * Asserts that the given entry begins at or after |
| 671 | * the specified address; if necessary, |
| 672 | * it splits the entry into two. |
| 673 | */ |
| 674 | #define vm_map_clip_start(map, entry, startaddr) \ |
| 675 | { \ |
| 676 | if (startaddr > entry->start) \ |
| 677 | _vm_map_clip_start(map, entry, startaddr); \ |
| 678 | } |
| 679 | |
| 680 | /* |
| 681 | * This routine is called only when it is known that |
| 682 | * the entry must be split. |
| 683 | */ |
| 684 | void _vm_map_clip_start(map, entry, start) |
| 685 | register vm_map_t map; |
| 686 | register vm_map_entry_t entry; |
| 687 | register vm_offset_t start; |
| 688 | { |
| 689 | register vm_map_entry_t new_entry; |
| 690 | |
| 691 | /* |
| 692 | * See if we can simplify this entry first |
| 693 | */ |
| 694 | |
| 695 | vm_map_simplify_entry(map, entry); |
| 696 | |
| 697 | /* |
| 698 | * Split off the front portion -- |
| 699 | * note that we must insert the new |
| 700 | * entry BEFORE this one, so that |
| 701 | * this entry has the specified starting |
| 702 | * address. |
| 703 | */ |
| 704 | |
| 705 | new_entry = vm_map_entry_create(map); |
| 706 | *new_entry = *entry; |
| 707 | |
| 708 | new_entry->end = start; |
| 709 | entry->offset += (start - entry->start); |
| 710 | entry->start = start; |
| 711 | |
| 712 | vm_map_entry_link(map, entry->prev, new_entry); |
| 713 | |
| 714 | if (entry->is_a_map || entry->is_sub_map) |
| 715 | vm_map_reference(new_entry->object.share_map); |
| 716 | else |
| 717 | vm_object_reference(new_entry->object.vm_object); |
| 718 | } |
| 719 | |
| 720 | /* |
| 721 | * vm_map_clip_end: [ internal use only ] |
| 722 | * |
| 723 | * Asserts that the given entry ends at or before |
| 724 | * the specified address; if necessary, |
| 725 | * it splits the entry into two. |
| 726 | */ |
| 727 | |
| 728 | void _vm_map_clip_end(); |
| 729 | #define vm_map_clip_end(map, entry, endaddr) \ |
| 730 | { \ |
| 731 | if (endaddr < entry->end) \ |
| 732 | _vm_map_clip_end(map, entry, endaddr); \ |
| 733 | } |
| 734 | |
| 735 | /* |
| 736 | * This routine is called only when it is known that |
| 737 | * the entry must be split. |
| 738 | */ |
| 739 | void _vm_map_clip_end(map, entry, end) |
| 740 | register vm_map_t map; |
| 741 | register vm_map_entry_t entry; |
| 742 | register vm_offset_t end; |
| 743 | { |
| 744 | register vm_map_entry_t new_entry; |
| 745 | |
| 746 | /* |
| 747 | * Create a new entry and insert it |
| 748 | * AFTER the specified entry |
| 749 | */ |
| 750 | |
| 751 | new_entry = vm_map_entry_create(map); |
| 752 | *new_entry = *entry; |
| 753 | |
| 754 | new_entry->start = entry->end = end; |
| 755 | new_entry->offset += (end - entry->start); |
| 756 | |
| 757 | vm_map_entry_link(map, entry, new_entry); |
| 758 | |
| 759 | if (entry->is_a_map || entry->is_sub_map) |
| 760 | vm_map_reference(new_entry->object.share_map); |
| 761 | else |
| 762 | vm_object_reference(new_entry->object.vm_object); |
| 763 | } |
| 764 | |
| 765 | /* |
| 766 | * VM_MAP_RANGE_CHECK: [ internal use only ] |
| 767 | * |
| 768 | * Asserts that the starting and ending region |
| 769 | * addresses fall within the valid range of the map. |
| 770 | */ |
| 771 | #define VM_MAP_RANGE_CHECK(map, start, end) \ |
| 772 | { \ |
| 773 | if (start < vm_map_min(map)) \ |
| 774 | start = vm_map_min(map); \ |
| 775 | if (end > vm_map_max(map)) \ |
| 776 | end = vm_map_max(map); \ |
| 777 | if (start > end) \ |
| 778 | start = end; \ |
| 779 | } |
| 780 | |
| 781 | /* |
| 782 | * vm_map_submap: [ kernel use only ] |
| 783 | * |
| 784 | * Mark the given range as handled by a subordinate map. |
| 785 | * |
| 786 | * This range must have been created with vm_map_find, |
| 787 | * and no other operations may have been performed on this |
| 788 | * range prior to calling vm_map_submap. |
| 789 | * |
| 790 | * Only a limited number of operations can be performed |
| 791 | * within this rage after calling vm_map_submap: |
| 792 | * vm_fault |
| 793 | * [Don't try vm_map_copy!] |
| 794 | * |
| 795 | * To remove a submapping, one must first remove the |
| 796 | * range from the superior map, and then destroy the |
| 797 | * submap (if desired). [Better yet, don't try it.] |
| 798 | */ |
| 799 | vm_map_submap(map, start, end, submap) |
| 800 | register vm_map_t map; |
| 801 | register vm_offset_t start; |
| 802 | register vm_offset_t end; |
| 803 | vm_map_t submap; |
| 804 | { |
| 805 | vm_map_entry_t entry; |
| 806 | register int result = KERN_INVALID_ARGUMENT; |
| 807 | |
| 808 | vm_map_lock(map); |
| 809 | |
| 810 | VM_MAP_RANGE_CHECK(map, start, end); |
| 811 | |
| 812 | if (vm_map_lookup_entry(map, start, &entry)) { |
| 813 | vm_map_clip_start(map, entry, start); |
| 814 | } |
| 815 | else |
| 816 | entry = entry->next; |
| 817 | |
| 818 | vm_map_clip_end(map, entry, end); |
| 819 | |
| 820 | if ((entry->start == start) && (entry->end == end) && |
| 821 | (!entry->is_a_map) && |
| 822 | (entry->object.vm_object == VM_OBJECT_NULL) && |
| 823 | (!entry->copy_on_write)) { |
| 824 | entry->is_a_map = FALSE; |
| 825 | entry->is_sub_map = TRUE; |
| 826 | vm_map_reference(entry->object.sub_map = submap); |
| 827 | result = KERN_SUCCESS; |
| 828 | } |
| 829 | vm_map_unlock(map); |
| 830 | |
| 831 | return(result); |
| 832 | } |
| 833 | |
| 834 | /* |
| 835 | * vm_map_protect: |
| 836 | * |
| 837 | * Sets the protection of the specified address |
| 838 | * region in the target map. If "set_max" is |
| 839 | * specified, the maximum protection is to be set; |
| 840 | * otherwise, only the current protection is affected. |
| 841 | */ |
| 842 | vm_map_protect(map, start, end, new_prot, set_max) |
| 843 | register vm_map_t map; |
| 844 | register vm_offset_t start; |
| 845 | register vm_offset_t end; |
| 846 | register vm_prot_t new_prot; |
| 847 | register boolean_t set_max; |
| 848 | { |
| 849 | register vm_map_entry_t current; |
| 850 | vm_map_entry_t entry; |
| 851 | |
| 852 | vm_map_lock(map); |
| 853 | |
| 854 | VM_MAP_RANGE_CHECK(map, start, end); |
| 855 | |
| 856 | if (vm_map_lookup_entry(map, start, &entry)) { |
| 857 | vm_map_clip_start(map, entry, start); |
| 858 | } |
| 859 | else |
| 860 | entry = entry->next; |
| 861 | |
| 862 | /* |
| 863 | * Make a first pass to check for protection |
| 864 | * violations. |
| 865 | */ |
| 866 | |
| 867 | current = entry; |
| 868 | while ((current != &map->header) && (current->start < end)) { |
| 869 | if (current->is_sub_map) |
| 870 | return(KERN_INVALID_ARGUMENT); |
| 871 | if ((new_prot & current->max_protection) != new_prot) { |
| 872 | vm_map_unlock(map); |
| 873 | return(KERN_PROTECTION_FAILURE); |
| 874 | } |
| 875 | |
| 876 | current = current->next; |
| 877 | } |
| 878 | |
| 879 | /* |
| 880 | * Go back and fix up protections. |
| 881 | * [Note that clipping is not necessary the second time.] |
| 882 | */ |
| 883 | |
| 884 | current = entry; |
| 885 | |
| 886 | while ((current != &map->header) && (current->start < end)) { |
| 887 | vm_prot_t old_prot; |
| 888 | |
| 889 | vm_map_clip_end(map, current, end); |
| 890 | |
| 891 | old_prot = current->protection; |
| 892 | if (set_max) |
| 893 | current->protection = |
| 894 | (current->max_protection = new_prot) & |
| 895 | old_prot; |
| 896 | else |
| 897 | current->protection = new_prot; |
| 898 | |
| 899 | /* |
| 900 | * Update physical map if necessary. |
| 901 | * Worry about copy-on-write here -- CHECK THIS XXX |
| 902 | */ |
| 903 | |
| 904 | if (current->protection != old_prot) { |
| 905 | |
| 906 | #define MASK(entry) ((entry)->copy_on_write ? ~VM_PROT_WRITE : \ |
| 907 | VM_PROT_ALL) |
| 908 | #define max(a,b) ((a) > (b) ? (a) : (b)) |
| 909 | |
| 910 | if (current->is_a_map) { |
| 911 | vm_map_entry_t share_entry; |
| 912 | vm_offset_t share_end; |
| 913 | |
| 914 | vm_map_lock(current->object.share_map); |
| 915 | (void) vm_map_lookup_entry( |
| 916 | current->object.share_map, |
| 917 | current->offset, |
| 918 | &share_entry); |
| 919 | share_end = current->offset + |
| 920 | (current->end - current->start); |
| 921 | while ((share_entry != |
| 922 | ¤t->object.share_map->header) && |
| 923 | (share_entry->start < share_end)) { |
| 924 | |
| 925 | pmap_protect(map->pmap, |
| 926 | (max(share_entry->start, |
| 927 | current->offset) - |
| 928 | current->offset + |
| 929 | current->start), |
| 930 | min(share_entry->end, |
| 931 | share_end) - |
| 932 | current->offset + |
| 933 | current->start, |
| 934 | current->protection & |
| 935 | MASK(share_entry)); |
| 936 | |
| 937 | share_entry = share_entry->next; |
| 938 | } |
| 939 | vm_map_unlock(current->object.share_map); |
| 940 | } |
| 941 | else |
| 942 | pmap_protect(map->pmap, current->start, |
| 943 | current->end, |
| 944 | current->protection & MASK(entry)); |
| 945 | #undef max |
| 946 | #undef MASK |
| 947 | } |
| 948 | current = current->next; |
| 949 | } |
| 950 | |
| 951 | vm_map_unlock(map); |
| 952 | return(KERN_SUCCESS); |
| 953 | } |
| 954 | |
| 955 | /* |
| 956 | * vm_map_inherit: |
| 957 | * |
| 958 | * Sets the inheritance of the specified address |
| 959 | * range in the target map. Inheritance |
| 960 | * affects how the map will be shared with |
| 961 | * child maps at the time of vm_map_fork. |
| 962 | */ |
| 963 | vm_map_inherit(map, start, end, new_inheritance) |
| 964 | register vm_map_t map; |
| 965 | register vm_offset_t start; |
| 966 | register vm_offset_t end; |
| 967 | register vm_inherit_t new_inheritance; |
| 968 | { |
| 969 | register vm_map_entry_t entry; |
| 970 | vm_map_entry_t temp_entry; |
| 971 | |
| 972 | switch (new_inheritance) { |
| 973 | case VM_INHERIT_NONE: |
| 974 | case VM_INHERIT_COPY: |
| 975 | case VM_INHERIT_SHARE: |
| 976 | break; |
| 977 | default: |
| 978 | return(KERN_INVALID_ARGUMENT); |
| 979 | } |
| 980 | |
| 981 | vm_map_lock(map); |
| 982 | |
| 983 | VM_MAP_RANGE_CHECK(map, start, end); |
| 984 | |
| 985 | if (vm_map_lookup_entry(map, start, &temp_entry)) { |
| 986 | entry = temp_entry; |
| 987 | vm_map_clip_start(map, entry, start); |
| 988 | } |
| 989 | else |
| 990 | entry = temp_entry->next; |
| 991 | |
| 992 | while ((entry != &map->header) && (entry->start < end)) { |
| 993 | vm_map_clip_end(map, entry, end); |
| 994 | |
| 995 | entry->inheritance = new_inheritance; |
| 996 | |
| 997 | entry = entry->next; |
| 998 | } |
| 999 | |
| 1000 | vm_map_unlock(map); |
| 1001 | return(KERN_SUCCESS); |
| 1002 | } |
| 1003 | |
| 1004 | /* |
| 1005 | * vm_map_pageable: |
| 1006 | * |
| 1007 | * Sets the pageability of the specified address |
| 1008 | * range in the target map. Regions specified |
| 1009 | * as not pageable require locked-down physical |
| 1010 | * memory and physical page maps. |
| 1011 | * |
| 1012 | * The map must not be locked, but a reference |
| 1013 | * must remain to the map throughout the call. |
| 1014 | */ |
| 1015 | vm_map_pageable(map, start, end, new_pageable) |
| 1016 | register vm_map_t map; |
| 1017 | register vm_offset_t start; |
| 1018 | register vm_offset_t end; |
| 1019 | register boolean_t new_pageable; |
| 1020 | { |
| 1021 | register vm_map_entry_t entry; |
| 1022 | vm_map_entry_t temp_entry; |
| 1023 | |
| 1024 | vm_map_lock(map); |
| 1025 | |
| 1026 | VM_MAP_RANGE_CHECK(map, start, end); |
| 1027 | |
| 1028 | /* |
| 1029 | * Only one pageability change may take place at one |
| 1030 | * time, since vm_fault assumes it will be called |
| 1031 | * only once for each wiring/unwiring. Therefore, we |
| 1032 | * have to make sure we're actually changing the pageability |
| 1033 | * for the entire region. We do so before making any changes. |
| 1034 | */ |
| 1035 | |
| 1036 | if (vm_map_lookup_entry(map, start, &temp_entry)) { |
| 1037 | entry = temp_entry; |
| 1038 | vm_map_clip_start(map, entry, start); |
| 1039 | } |
| 1040 | else |
| 1041 | entry = temp_entry->next; |
| 1042 | temp_entry = entry; |
| 1043 | |
| 1044 | /* |
| 1045 | * Actions are rather different for wiring and unwiring, |
| 1046 | * so we have two separate cases. |
| 1047 | */ |
| 1048 | |
| 1049 | if (new_pageable) { |
| 1050 | |
| 1051 | /* |
| 1052 | * Unwiring. First ensure that the range to be |
| 1053 | * unwired is really wired down. |
| 1054 | */ |
| 1055 | while ((entry != &map->header) && (entry->start < end)) { |
| 1056 | |
| 1057 | if (entry->wired_count == 0) { |
| 1058 | vm_map_unlock(map); |
| 1059 | return(KERN_INVALID_ARGUMENT); |
| 1060 | } |
| 1061 | entry = entry->next; |
| 1062 | } |
| 1063 | |
| 1064 | /* |
| 1065 | * Now decrement the wiring count for each region. |
| 1066 | * If a region becomes completely unwired, |
| 1067 | * unwire its physical pages and mappings. |
| 1068 | */ |
| 1069 | lock_set_recursive(&map->lock); |
| 1070 | |
| 1071 | entry = temp_entry; |
| 1072 | while ((entry != &map->header) && (entry->start < end)) { |
| 1073 | vm_map_clip_end(map, entry, end); |
| 1074 | |
| 1075 | entry->wired_count--; |
| 1076 | if (entry->wired_count == 0) |
| 1077 | vm_fault_unwire(map, entry->start, entry->end); |
| 1078 | |
| 1079 | entry = entry->next; |
| 1080 | } |
| 1081 | lock_clear_recursive(&map->lock); |
| 1082 | } |
| 1083 | |
| 1084 | else { |
| 1085 | /* |
| 1086 | * Wiring. We must do this in two passes: |
| 1087 | * |
| 1088 | * 1. Holding the write lock, we increment the |
| 1089 | * wiring count. For any area that is not already |
| 1090 | * wired, we create any shadow objects that need |
| 1091 | * to be created. |
| 1092 | * |
| 1093 | * 2. We downgrade to a read lock, and call |
| 1094 | * vm_fault_wire to fault in the pages for any |
| 1095 | * newly wired area (wired_count is 1). |
| 1096 | * |
| 1097 | * Downgrading to a read lock for vm_fault_wire avoids |
| 1098 | * a possible deadlock with another thread that may have |
| 1099 | * faulted on one of the pages to be wired (it would mark |
| 1100 | * the page busy, blocking us, then in turn block on the |
| 1101 | * map lock that we hold). Because of problems in the |
| 1102 | * recursive lock package, we cannot upgrade to a write |
| 1103 | * lock in vm_map_lookup. Thus, any actions that require |
| 1104 | * the write lock must be done beforehand. Because we |
| 1105 | * keep the read lock on the map, the copy-on-write status |
| 1106 | * of the entries we modify here cannot change. |
| 1107 | */ |
| 1108 | |
| 1109 | /* |
| 1110 | * Pass 1. |
| 1111 | */ |
| 1112 | entry = temp_entry; |
| 1113 | while ((entry != &map->header) && (entry->start < end)) { |
| 1114 | vm_map_clip_end(map, entry, end); |
| 1115 | |
| 1116 | entry->wired_count++; |
| 1117 | if (entry->wired_count == 1) { |
| 1118 | |
| 1119 | /* |
| 1120 | * Perform actions of vm_map_lookup that need |
| 1121 | * the write lock on the map: create a shadow |
| 1122 | * object for a copy-on-write region, or an |
| 1123 | * object for a zero-fill region. |
| 1124 | * |
| 1125 | * We don't have to do this for entries that |
| 1126 | * point to sharing maps, because we won't hold |
| 1127 | * the lock on the sharing map. |
| 1128 | */ |
| 1129 | if (!entry->is_a_map) { |
| 1130 | if (entry->needs_copy && |
| 1131 | ((entry->protection & VM_PROT_WRITE) != 0)) { |
| 1132 | |
| 1133 | vm_object_shadow(&entry->object.vm_object, |
| 1134 | &entry->offset, |
| 1135 | (vm_size_t)(entry->end |
| 1136 | - entry->start)); |
| 1137 | entry->needs_copy = FALSE; |
| 1138 | } |
| 1139 | else if (entry->object.vm_object == VM_OBJECT_NULL) { |
| 1140 | entry->object.vm_object = |
| 1141 | vm_object_allocate((vm_size_t)(entry->end |
| 1142 | - entry->start)); |
| 1143 | entry->offset = (vm_offset_t)0; |
| 1144 | } |
| 1145 | } |
| 1146 | } |
| 1147 | |
| 1148 | entry = entry->next; |
| 1149 | } |
| 1150 | |
| 1151 | /* |
| 1152 | * Pass 2. |
| 1153 | */ |
| 1154 | |
| 1155 | /* |
| 1156 | * HACK HACK HACK HACK |
| 1157 | * |
| 1158 | * If we are wiring in the kernel map or a submap of it, |
| 1159 | * unlock the map to avoid deadlocks. We trust that the |
| 1160 | * kernel threads are well-behaved, and therefore will |
| 1161 | * not do anything destructive to this region of the map |
| 1162 | * while we have it unlocked. We cannot trust user threads |
| 1163 | * to do the same. |
| 1164 | * |
| 1165 | * HACK HACK HACK HACK |
| 1166 | */ |
| 1167 | if (vm_map_pmap(map) == kernel_pmap) { |
| 1168 | vm_map_unlock(map); /* trust me ... */ |
| 1169 | } |
| 1170 | else { |
| 1171 | lock_set_recursive(&map->lock); |
| 1172 | lock_write_to_read(&map->lock); |
| 1173 | } |
| 1174 | |
| 1175 | entry = temp_entry; |
| 1176 | while (entry != &map->header && entry->start < end) { |
| 1177 | if (entry->wired_count == 1) { |
| 1178 | vm_fault_wire(map, entry->start, entry->end); |
| 1179 | } |
| 1180 | entry = entry->next; |
| 1181 | } |
| 1182 | |
| 1183 | if (vm_map_pmap(map) == kernel_pmap) { |
| 1184 | vm_map_lock(map); |
| 1185 | } |
| 1186 | else { |
| 1187 | lock_clear_recursive(&map->lock); |
| 1188 | } |
| 1189 | } |
| 1190 | |
| 1191 | vm_map_unlock(map); |
| 1192 | |
| 1193 | return(KERN_SUCCESS); |
| 1194 | } |
| 1195 | |
| 1196 | /* |
| 1197 | * vm_map_entry_unwire: [ internal use only ] |
| 1198 | * |
| 1199 | * Make the region specified by this entry pageable. |
| 1200 | * |
| 1201 | * The map in question should be locked. |
| 1202 | * [This is the reason for this routine's existence.] |
| 1203 | */ |
| 1204 | void vm_map_entry_unwire(map, entry) |
| 1205 | vm_map_t map; |
| 1206 | register vm_map_entry_t entry; |
| 1207 | { |
| 1208 | vm_fault_unwire(map, entry->start, entry->end); |
| 1209 | entry->wired_count = 0; |
| 1210 | } |
| 1211 | |
| 1212 | /* |
| 1213 | * vm_map_entry_delete: [ internal use only ] |
| 1214 | * |
| 1215 | * Deallocate the given entry from the target map. |
| 1216 | */ |
| 1217 | void vm_map_entry_delete(map, entry) |
| 1218 | register vm_map_t map; |
| 1219 | register vm_map_entry_t entry; |
| 1220 | { |
| 1221 | if (entry->wired_count != 0) |
| 1222 | vm_map_entry_unwire(map, entry); |
| 1223 | |
| 1224 | vm_map_entry_unlink(map, entry); |
| 1225 | map->size -= entry->end - entry->start; |
| 1226 | |
| 1227 | if (entry->is_a_map || entry->is_sub_map) |
| 1228 | vm_map_deallocate(entry->object.share_map); |
| 1229 | else |
| 1230 | vm_object_deallocate(entry->object.vm_object); |
| 1231 | |
| 1232 | vm_map_entry_dispose(map, entry); |
| 1233 | } |
| 1234 | |
| 1235 | /* |
| 1236 | * vm_map_delete: [ internal use only ] |
| 1237 | * |
| 1238 | * Deallocates the given address range from the target |
| 1239 | * map. |
| 1240 | * |
| 1241 | * When called with a sharing map, removes pages from |
| 1242 | * that region from all physical maps. |
| 1243 | */ |
| 1244 | vm_map_delete(map, start, end) |
| 1245 | register vm_map_t map; |
| 1246 | vm_offset_t start; |
| 1247 | register vm_offset_t end; |
| 1248 | { |
| 1249 | register vm_map_entry_t entry; |
| 1250 | vm_map_entry_t first_entry; |
| 1251 | |
| 1252 | /* |
| 1253 | * Find the start of the region, and clip it |
| 1254 | */ |
| 1255 | |
| 1256 | if (!vm_map_lookup_entry(map, start, &first_entry)) |
| 1257 | entry = first_entry->next; |
| 1258 | else { |
| 1259 | entry = first_entry; |
| 1260 | vm_map_clip_start(map, entry, start); |
| 1261 | |
| 1262 | /* |
| 1263 | * Fix the lookup hint now, rather than each |
| 1264 | * time though the loop. |
| 1265 | */ |
| 1266 | |
| 1267 | SAVE_HINT(map, entry->prev); |
| 1268 | } |
| 1269 | |
| 1270 | /* |
| 1271 | * Save the free space hint |
| 1272 | */ |
| 1273 | |
| 1274 | if (map->first_free->start >= start) |
| 1275 | map->first_free = entry->prev; |
| 1276 | |
| 1277 | /* |
| 1278 | * Step through all entries in this region |
| 1279 | */ |
| 1280 | |
| 1281 | while ((entry != &map->header) && (entry->start < end)) { |
| 1282 | vm_map_entry_t next; |
| 1283 | register vm_offset_t s, e; |
| 1284 | register vm_object_t object; |
| 1285 | |
| 1286 | vm_map_clip_end(map, entry, end); |
| 1287 | |
| 1288 | next = entry->next; |
| 1289 | s = entry->start; |
| 1290 | e = entry->end; |
| 1291 | |
| 1292 | /* |
| 1293 | * Unwire before removing addresses from the pmap; |
| 1294 | * otherwise, unwiring will put the entries back in |
| 1295 | * the pmap. |
| 1296 | */ |
| 1297 | |
| 1298 | object = entry->object.vm_object; |
| 1299 | if (entry->wired_count != 0) |
| 1300 | vm_map_entry_unwire(map, entry); |
| 1301 | |
| 1302 | /* |
| 1303 | * If this is a sharing map, we must remove |
| 1304 | * *all* references to this data, since we can't |
| 1305 | * find all of the physical maps which are sharing |
| 1306 | * it. |
| 1307 | */ |
| 1308 | |
| 1309 | if (object == kernel_object || object == kmem_object) |
| 1310 | vm_object_page_remove(object, entry->offset, |
| 1311 | entry->offset + (e - s)); |
| 1312 | else if (!map->is_main_map) |
| 1313 | vm_object_pmap_remove(object, |
| 1314 | entry->offset, |
| 1315 | entry->offset + (e - s)); |
| 1316 | else |
| 1317 | pmap_remove(map->pmap, s, e); |
| 1318 | |
| 1319 | /* |
| 1320 | * Delete the entry (which may delete the object) |
| 1321 | * only after removing all pmap entries pointing |
| 1322 | * to its pages. (Otherwise, its page frames may |
| 1323 | * be reallocated, and any modify bits will be |
| 1324 | * set in the wrong object!) |
| 1325 | */ |
| 1326 | |
| 1327 | vm_map_entry_delete(map, entry); |
| 1328 | entry = next; |
| 1329 | } |
| 1330 | return(KERN_SUCCESS); |
| 1331 | } |
| 1332 | |
| 1333 | /* |
| 1334 | * vm_map_remove: |
| 1335 | * |
| 1336 | * Remove the given address range from the target map. |
| 1337 | * This is the exported form of vm_map_delete. |
| 1338 | */ |
| 1339 | vm_map_remove(map, start, end) |
| 1340 | register vm_map_t map; |
| 1341 | register vm_offset_t start; |
| 1342 | register vm_offset_t end; |
| 1343 | { |
| 1344 | register int result; |
| 1345 | |
| 1346 | vm_map_lock(map); |
| 1347 | VM_MAP_RANGE_CHECK(map, start, end); |
| 1348 | result = vm_map_delete(map, start, end); |
| 1349 | vm_map_unlock(map); |
| 1350 | |
| 1351 | return(result); |
| 1352 | } |
| 1353 | |
| 1354 | /* |
| 1355 | * vm_map_check_protection: |
| 1356 | * |
| 1357 | * Assert that the target map allows the specified |
| 1358 | * privilege on the entire address region given. |
| 1359 | * The entire region must be allocated. |
| 1360 | */ |
| 1361 | boolean_t vm_map_check_protection(map, start, end, protection) |
| 1362 | register vm_map_t map; |
| 1363 | register vm_offset_t start; |
| 1364 | register vm_offset_t end; |
| 1365 | register vm_prot_t protection; |
| 1366 | { |
| 1367 | register vm_map_entry_t entry; |
| 1368 | vm_map_entry_t tmp_entry; |
| 1369 | |
| 1370 | if (!vm_map_lookup_entry(map, start, &tmp_entry)) { |
| 1371 | return(FALSE); |
| 1372 | } |
| 1373 | |
| 1374 | entry = tmp_entry; |
| 1375 | |
| 1376 | while (start < end) { |
| 1377 | if (entry == &map->header) { |
| 1378 | return(FALSE); |
| 1379 | } |
| 1380 | |
| 1381 | /* |
| 1382 | * No holes allowed! |
| 1383 | */ |
| 1384 | |
| 1385 | if (start < entry->start) { |
| 1386 | return(FALSE); |
| 1387 | } |
| 1388 | |
| 1389 | /* |
| 1390 | * Check protection associated with entry. |
| 1391 | */ |
| 1392 | |
| 1393 | if ((entry->protection & protection) != protection) { |
| 1394 | return(FALSE); |
| 1395 | } |
| 1396 | |
| 1397 | /* go to next entry */ |
| 1398 | |
| 1399 | start = entry->end; |
| 1400 | entry = entry->next; |
| 1401 | } |
| 1402 | return(TRUE); |
| 1403 | } |
| 1404 | |
| 1405 | /* |
| 1406 | * vm_map_copy_entry: |
| 1407 | * |
| 1408 | * Copies the contents of the source entry to the destination |
| 1409 | * entry. The entries *must* be aligned properly. |
| 1410 | */ |
| 1411 | void vm_map_copy_entry(src_map, dst_map, src_entry, dst_entry) |
| 1412 | vm_map_t src_map, dst_map; |
| 1413 | register vm_map_entry_t src_entry, dst_entry; |
| 1414 | { |
| 1415 | vm_object_t temp_object; |
| 1416 | |
| 1417 | if (src_entry->is_sub_map || dst_entry->is_sub_map) |
| 1418 | return; |
| 1419 | |
| 1420 | if (dst_entry->object.vm_object != VM_OBJECT_NULL && |
| 1421 | !dst_entry->object.vm_object->internal) |
| 1422 | printf("vm_map_copy_entry: copying over permanent data!\n"); |
| 1423 | |
| 1424 | /* |
| 1425 | * If our destination map was wired down, |
| 1426 | * unwire it now. |
| 1427 | */ |
| 1428 | |
| 1429 | if (dst_entry->wired_count != 0) |
| 1430 | vm_map_entry_unwire(dst_map, dst_entry); |
| 1431 | |
| 1432 | /* |
| 1433 | * If we're dealing with a sharing map, we |
| 1434 | * must remove the destination pages from |
| 1435 | * all maps (since we cannot know which maps |
| 1436 | * this sharing map belongs in). |
| 1437 | */ |
| 1438 | |
| 1439 | if (dst_map->is_main_map) |
| 1440 | pmap_remove(dst_map->pmap, dst_entry->start, dst_entry->end); |
| 1441 | else |
| 1442 | vm_object_pmap_remove(dst_entry->object.vm_object, |
| 1443 | dst_entry->offset, |
| 1444 | dst_entry->offset + |
| 1445 | (dst_entry->end - dst_entry->start)); |
| 1446 | |
| 1447 | if (src_entry->wired_count == 0) { |
| 1448 | |
| 1449 | boolean_t src_needs_copy; |
| 1450 | |
| 1451 | /* |
| 1452 | * If the source entry is marked needs_copy, |
| 1453 | * it is already write-protected. |
| 1454 | */ |
| 1455 | if (!src_entry->needs_copy) { |
| 1456 | |
| 1457 | boolean_t su; |
| 1458 | |
| 1459 | /* |
| 1460 | * If the source entry has only one mapping, |
| 1461 | * we can just protect the virtual address |
| 1462 | * range. |
| 1463 | */ |
| 1464 | if (!(su = src_map->is_main_map)) { |
| 1465 | simple_lock(&src_map->ref_lock); |
| 1466 | su = (src_map->ref_count == 1); |
| 1467 | simple_unlock(&src_map->ref_lock); |
| 1468 | } |
| 1469 | |
| 1470 | if (su) { |
| 1471 | pmap_protect(src_map->pmap, |
| 1472 | src_entry->start, |
| 1473 | src_entry->end, |
| 1474 | src_entry->protection & ~VM_PROT_WRITE); |
| 1475 | } |
| 1476 | else { |
| 1477 | vm_object_pmap_copy(src_entry->object.vm_object, |
| 1478 | src_entry->offset, |
| 1479 | src_entry->offset + (src_entry->end |
| 1480 | -src_entry->start)); |
| 1481 | } |
| 1482 | } |
| 1483 | |
| 1484 | /* |
| 1485 | * Make a copy of the object. |
| 1486 | */ |
| 1487 | temp_object = dst_entry->object.vm_object; |
| 1488 | vm_object_copy(src_entry->object.vm_object, |
| 1489 | src_entry->offset, |
| 1490 | (vm_size_t)(src_entry->end - |
| 1491 | src_entry->start), |
| 1492 | &dst_entry->object.vm_object, |
| 1493 | &dst_entry->offset, |
| 1494 | &src_needs_copy); |
| 1495 | /* |
| 1496 | * If we didn't get a copy-object now, mark the |
| 1497 | * source map entry so that a shadow will be created |
| 1498 | * to hold its changed pages. |
| 1499 | */ |
| 1500 | if (src_needs_copy) |
| 1501 | src_entry->needs_copy = TRUE; |
| 1502 | |
| 1503 | /* |
| 1504 | * The destination always needs to have a shadow |
| 1505 | * created. |
| 1506 | */ |
| 1507 | dst_entry->needs_copy = TRUE; |
| 1508 | |
| 1509 | /* |
| 1510 | * Mark the entries copy-on-write, so that write-enabling |
| 1511 | * the entry won't make copy-on-write pages writable. |
| 1512 | */ |
| 1513 | src_entry->copy_on_write = TRUE; |
| 1514 | dst_entry->copy_on_write = TRUE; |
| 1515 | /* |
| 1516 | * Get rid of the old object. |
| 1517 | */ |
| 1518 | vm_object_deallocate(temp_object); |
| 1519 | |
| 1520 | pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start, |
| 1521 | dst_entry->end - dst_entry->start, src_entry->start); |
| 1522 | } |
| 1523 | else { |
| 1524 | /* |
| 1525 | * Of course, wired down pages can't be set copy-on-write. |
| 1526 | * Cause wired pages to be copied into the new |
| 1527 | * map by simulating faults (the new pages are |
| 1528 | * pageable) |
| 1529 | */ |
| 1530 | vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry); |
| 1531 | } |
| 1532 | } |
| 1533 | |
| 1534 | /* |
| 1535 | * vm_map_copy: |
| 1536 | * |
| 1537 | * Perform a virtual memory copy from the source |
| 1538 | * address map/range to the destination map/range. |
| 1539 | * |
| 1540 | * If src_destroy or dst_alloc is requested, |
| 1541 | * the source and destination regions should be |
| 1542 | * disjoint, not only in the top-level map, but |
| 1543 | * in the sharing maps as well. [The best way |
| 1544 | * to guarantee this is to use a new intermediate |
| 1545 | * map to make copies. This also reduces map |
| 1546 | * fragmentation.] |
| 1547 | */ |
| 1548 | vm_map_copy(dst_map, src_map, |
| 1549 | dst_addr, len, src_addr, |
| 1550 | dst_alloc, src_destroy) |
| 1551 | vm_map_t dst_map; |
| 1552 | vm_map_t src_map; |
| 1553 | vm_offset_t dst_addr; |
| 1554 | vm_size_t len; |
| 1555 | vm_offset_t src_addr; |
| 1556 | boolean_t dst_alloc; |
| 1557 | boolean_t src_destroy; |
| 1558 | { |
| 1559 | register |
| 1560 | vm_map_entry_t src_entry; |
| 1561 | register |
| 1562 | vm_map_entry_t dst_entry; |
| 1563 | vm_map_entry_t tmp_entry; |
| 1564 | vm_offset_t src_start; |
| 1565 | vm_offset_t src_end; |
| 1566 | vm_offset_t dst_start; |
| 1567 | vm_offset_t dst_end; |
| 1568 | vm_offset_t src_clip; |
| 1569 | vm_offset_t dst_clip; |
| 1570 | int result; |
| 1571 | boolean_t old_src_destroy; |
| 1572 | |
| 1573 | /* |
| 1574 | * XXX While we figure out why src_destroy screws up, |
| 1575 | * we'll do it by explicitly vm_map_delete'ing at the end. |
| 1576 | */ |
| 1577 | |
| 1578 | old_src_destroy = src_destroy; |
| 1579 | src_destroy = FALSE; |
| 1580 | |
| 1581 | /* |
| 1582 | * Compute start and end of region in both maps |
| 1583 | */ |
| 1584 | |
| 1585 | src_start = src_addr; |
| 1586 | src_end = src_start + len; |
| 1587 | dst_start = dst_addr; |
| 1588 | dst_end = dst_start + len; |
| 1589 | |
| 1590 | /* |
| 1591 | * Check that the region can exist in both source |
| 1592 | * and destination. |
| 1593 | */ |
| 1594 | |
| 1595 | if ((dst_end < dst_start) || (src_end < src_start)) |
| 1596 | return(KERN_NO_SPACE); |
| 1597 | |
| 1598 | /* |
| 1599 | * Lock the maps in question -- we avoid deadlock |
| 1600 | * by ordering lock acquisition by map value |
| 1601 | */ |
| 1602 | |
| 1603 | if (src_map == dst_map) { |
| 1604 | vm_map_lock(src_map); |
| 1605 | } |
| 1606 | else if ((int) src_map < (int) dst_map) { |
| 1607 | vm_map_lock(src_map); |
| 1608 | vm_map_lock(dst_map); |
| 1609 | } else { |
| 1610 | vm_map_lock(dst_map); |
| 1611 | vm_map_lock(src_map); |
| 1612 | } |
| 1613 | |
| 1614 | result = KERN_SUCCESS; |
| 1615 | |
| 1616 | /* |
| 1617 | * Check protections... source must be completely readable and |
| 1618 | * destination must be completely writable. [Note that if we're |
| 1619 | * allocating the destination region, we don't have to worry |
| 1620 | * about protection, but instead about whether the region |
| 1621 | * exists.] |
| 1622 | */ |
| 1623 | |
| 1624 | if (src_map->is_main_map && dst_map->is_main_map) { |
| 1625 | if (!vm_map_check_protection(src_map, src_start, src_end, |
| 1626 | VM_PROT_READ)) { |
| 1627 | result = KERN_PROTECTION_FAILURE; |
| 1628 | goto Return; |
| 1629 | } |
| 1630 | |
| 1631 | if (dst_alloc) { |
| 1632 | /* XXX Consider making this a vm_map_find instead */ |
| 1633 | if ((result = vm_map_insert(dst_map, VM_OBJECT_NULL, |
| 1634 | (vm_offset_t) 0, dst_start, dst_end)) != KERN_SUCCESS) |
| 1635 | goto Return; |
| 1636 | } |
| 1637 | else if (!vm_map_check_protection(dst_map, dst_start, dst_end, |
| 1638 | VM_PROT_WRITE)) { |
| 1639 | result = KERN_PROTECTION_FAILURE; |
| 1640 | goto Return; |
| 1641 | } |
| 1642 | } |
| 1643 | |
| 1644 | /* |
| 1645 | * Find the start entries and clip. |
| 1646 | * |
| 1647 | * Note that checking protection asserts that the |
| 1648 | * lookup cannot fail. |
| 1649 | * |
| 1650 | * Also note that we wait to do the second lookup |
| 1651 | * until we have done the first clip, as the clip |
| 1652 | * may affect which entry we get! |
| 1653 | */ |
| 1654 | |
| 1655 | (void) vm_map_lookup_entry(src_map, src_addr, &tmp_entry); |
| 1656 | src_entry = tmp_entry; |
| 1657 | vm_map_clip_start(src_map, src_entry, src_start); |
| 1658 | |
| 1659 | (void) vm_map_lookup_entry(dst_map, dst_addr, &tmp_entry); |
| 1660 | dst_entry = tmp_entry; |
| 1661 | vm_map_clip_start(dst_map, dst_entry, dst_start); |
| 1662 | |
| 1663 | /* |
| 1664 | * If both source and destination entries are the same, |
| 1665 | * retry the first lookup, as it may have changed. |
| 1666 | */ |
| 1667 | |
| 1668 | if (src_entry == dst_entry) { |
| 1669 | (void) vm_map_lookup_entry(src_map, src_addr, &tmp_entry); |
| 1670 | src_entry = tmp_entry; |
| 1671 | } |
| 1672 | |
| 1673 | /* |
| 1674 | * If source and destination entries are still the same, |
| 1675 | * a null copy is being performed. |
| 1676 | */ |
| 1677 | |
| 1678 | if (src_entry == dst_entry) |
| 1679 | goto Return; |
| 1680 | |
| 1681 | /* |
| 1682 | * Go through entries until we get to the end of the |
| 1683 | * region. |
| 1684 | */ |
| 1685 | |
| 1686 | while (src_start < src_end) { |
| 1687 | /* |
| 1688 | * Clip the entries to the endpoint of the entire region. |
| 1689 | */ |
| 1690 | |
| 1691 | vm_map_clip_end(src_map, src_entry, src_end); |
| 1692 | vm_map_clip_end(dst_map, dst_entry, dst_end); |
| 1693 | |
| 1694 | /* |
| 1695 | * Clip each entry to the endpoint of the other entry. |
| 1696 | */ |
| 1697 | |
| 1698 | src_clip = src_entry->start + (dst_entry->end - dst_entry->start); |
| 1699 | vm_map_clip_end(src_map, src_entry, src_clip); |
| 1700 | |
| 1701 | dst_clip = dst_entry->start + (src_entry->end - src_entry->start); |
| 1702 | vm_map_clip_end(dst_map, dst_entry, dst_clip); |
| 1703 | |
| 1704 | /* |
| 1705 | * Both entries now match in size and relative endpoints. |
| 1706 | * |
| 1707 | * If both entries refer to a VM object, we can |
| 1708 | * deal with them now. |
| 1709 | */ |
| 1710 | |
| 1711 | if (!src_entry->is_a_map && !dst_entry->is_a_map) { |
| 1712 | vm_map_copy_entry(src_map, dst_map, src_entry, |
| 1713 | dst_entry); |
| 1714 | } |
| 1715 | else { |
| 1716 | register vm_map_t new_dst_map; |
| 1717 | vm_offset_t new_dst_start; |
| 1718 | vm_size_t new_size; |
| 1719 | vm_map_t new_src_map; |
| 1720 | vm_offset_t new_src_start; |
| 1721 | |
| 1722 | /* |
| 1723 | * We have to follow at least one sharing map. |
| 1724 | */ |
| 1725 | |
| 1726 | new_size = (dst_entry->end - dst_entry->start); |
| 1727 | |
| 1728 | if (src_entry->is_a_map) { |
| 1729 | new_src_map = src_entry->object.share_map; |
| 1730 | new_src_start = src_entry->offset; |
| 1731 | } |
| 1732 | else { |
| 1733 | new_src_map = src_map; |
| 1734 | new_src_start = src_entry->start; |
| 1735 | lock_set_recursive(&src_map->lock); |
| 1736 | } |
| 1737 | |
| 1738 | if (dst_entry->is_a_map) { |
| 1739 | vm_offset_t new_dst_end; |
| 1740 | |
| 1741 | new_dst_map = dst_entry->object.share_map; |
| 1742 | new_dst_start = dst_entry->offset; |
| 1743 | |
| 1744 | /* |
| 1745 | * Since the destination sharing entries |
| 1746 | * will be merely deallocated, we can |
| 1747 | * do that now, and replace the region |
| 1748 | * with a null object. [This prevents |
| 1749 | * splitting the source map to match |
| 1750 | * the form of the destination map.] |
| 1751 | * Note that we can only do so if the |
| 1752 | * source and destination do not overlap. |
| 1753 | */ |
| 1754 | |
| 1755 | new_dst_end = new_dst_start + new_size; |
| 1756 | |
| 1757 | if (new_dst_map != new_src_map) { |
| 1758 | vm_map_lock(new_dst_map); |
| 1759 | (void) vm_map_delete(new_dst_map, |
| 1760 | new_dst_start, |
| 1761 | new_dst_end); |
| 1762 | (void) vm_map_insert(new_dst_map, |
| 1763 | VM_OBJECT_NULL, |
| 1764 | (vm_offset_t) 0, |
| 1765 | new_dst_start, |
| 1766 | new_dst_end); |
| 1767 | vm_map_unlock(new_dst_map); |
| 1768 | } |
| 1769 | } |
| 1770 | else { |
| 1771 | new_dst_map = dst_map; |
| 1772 | new_dst_start = dst_entry->start; |
| 1773 | lock_set_recursive(&dst_map->lock); |
| 1774 | } |
| 1775 | |
| 1776 | /* |
| 1777 | * Recursively copy the sharing map. |
| 1778 | */ |
| 1779 | |
| 1780 | (void) vm_map_copy(new_dst_map, new_src_map, |
| 1781 | new_dst_start, new_size, new_src_start, |
| 1782 | FALSE, FALSE); |
| 1783 | |
| 1784 | if (dst_map == new_dst_map) |
| 1785 | lock_clear_recursive(&dst_map->lock); |
| 1786 | if (src_map == new_src_map) |
| 1787 | lock_clear_recursive(&src_map->lock); |
| 1788 | } |
| 1789 | |
| 1790 | /* |
| 1791 | * Update variables for next pass through the loop. |
| 1792 | */ |
| 1793 | |
| 1794 | src_start = src_entry->end; |
| 1795 | src_entry = src_entry->next; |
| 1796 | dst_start = dst_entry->end; |
| 1797 | dst_entry = dst_entry->next; |
| 1798 | |
| 1799 | /* |
| 1800 | * If the source is to be destroyed, here is the |
| 1801 | * place to do it. |
| 1802 | */ |
| 1803 | |
| 1804 | if (src_destroy && src_map->is_main_map && |
| 1805 | dst_map->is_main_map) |
| 1806 | vm_map_entry_delete(src_map, src_entry->prev); |
| 1807 | } |
| 1808 | |
| 1809 | /* |
| 1810 | * Update the physical maps as appropriate |
| 1811 | */ |
| 1812 | |
| 1813 | if (src_map->is_main_map && dst_map->is_main_map) { |
| 1814 | if (src_destroy) |
| 1815 | pmap_remove(src_map->pmap, src_addr, src_addr + len); |
| 1816 | } |
| 1817 | |
| 1818 | /* |
| 1819 | * Unlock the maps |
| 1820 | */ |
| 1821 | |
| 1822 | Return: ; |
| 1823 | |
| 1824 | if (old_src_destroy) |
| 1825 | vm_map_delete(src_map, src_addr, src_addr + len); |
| 1826 | |
| 1827 | vm_map_unlock(src_map); |
| 1828 | if (src_map != dst_map) |
| 1829 | vm_map_unlock(dst_map); |
| 1830 | |
| 1831 | return(result); |
| 1832 | } |
| 1833 | |
| 1834 | /* |
| 1835 | * vm_map_fork: |
| 1836 | * |
| 1837 | * Create and return a new map based on the old |
| 1838 | * map, according to the inheritance values on the |
| 1839 | * regions in that map. |
| 1840 | * |
| 1841 | * The source map must not be locked. |
| 1842 | */ |
| 1843 | vm_map_t vm_map_fork(old_map) |
| 1844 | vm_map_t old_map; |
| 1845 | { |
| 1846 | vm_map_t new_map; |
| 1847 | vm_map_entry_t old_entry; |
| 1848 | vm_map_entry_t new_entry; |
| 1849 | pmap_t new_pmap; |
| 1850 | |
| 1851 | vm_map_lock(old_map); |
| 1852 | |
| 1853 | new_pmap = pmap_create((vm_size_t) 0); |
| 1854 | new_map = vm_map_create(new_pmap, |
| 1855 | old_map->min_offset, |
| 1856 | old_map->max_offset, |
| 1857 | old_map->entries_pageable); |
| 1858 | |
| 1859 | old_entry = old_map->header.next; |
| 1860 | |
| 1861 | while (old_entry != &old_map->header) { |
| 1862 | if (old_entry->is_sub_map) |
| 1863 | panic("vm_map_fork: encountered a submap"); |
| 1864 | |
| 1865 | switch (old_entry->inheritance) { |
| 1866 | case VM_INHERIT_NONE: |
| 1867 | break; |
| 1868 | |
| 1869 | case VM_INHERIT_SHARE: |
| 1870 | /* |
| 1871 | * If we don't already have a sharing map: |
| 1872 | */ |
| 1873 | |
| 1874 | if (!old_entry->is_a_map) { |
| 1875 | vm_map_t new_share_map; |
| 1876 | vm_map_entry_t new_share_entry; |
| 1877 | |
| 1878 | /* |
| 1879 | * Create a new sharing map |
| 1880 | */ |
| 1881 | |
| 1882 | new_share_map = vm_map_create(PMAP_NULL, |
| 1883 | old_entry->start, |
| 1884 | old_entry->end, |
| 1885 | TRUE); |
| 1886 | new_share_map->is_main_map = FALSE; |
| 1887 | |
| 1888 | /* |
| 1889 | * Create the only sharing entry from the |
| 1890 | * old task map entry. |
| 1891 | */ |
| 1892 | |
| 1893 | new_share_entry = |
| 1894 | vm_map_entry_create(new_share_map); |
| 1895 | *new_share_entry = *old_entry; |
| 1896 | |
| 1897 | /* |
| 1898 | * Insert the entry into the new sharing |
| 1899 | * map |
| 1900 | */ |
| 1901 | |
| 1902 | vm_map_entry_link(new_share_map, |
| 1903 | new_share_map->header.prev, |
| 1904 | new_share_entry); |
| 1905 | |
| 1906 | /* |
| 1907 | * Fix up the task map entry to refer |
| 1908 | * to the sharing map now. |
| 1909 | */ |
| 1910 | |
| 1911 | old_entry->is_a_map = TRUE; |
| 1912 | old_entry->object.share_map = new_share_map; |
| 1913 | old_entry->offset = old_entry->start; |
| 1914 | } |
| 1915 | |
| 1916 | /* |
| 1917 | * Clone the entry, referencing the sharing map. |
| 1918 | */ |
| 1919 | |
| 1920 | new_entry = vm_map_entry_create(new_map); |
| 1921 | *new_entry = *old_entry; |
| 1922 | vm_map_reference(new_entry->object.share_map); |
| 1923 | |
| 1924 | /* |
| 1925 | * Insert the entry into the new map -- we |
| 1926 | * know we're inserting at the end of the new |
| 1927 | * map. |
| 1928 | */ |
| 1929 | |
| 1930 | vm_map_entry_link(new_map, new_map->header.prev, |
| 1931 | new_entry); |
| 1932 | |
| 1933 | /* |
| 1934 | * Update the physical map |
| 1935 | */ |
| 1936 | |
| 1937 | pmap_copy(new_map->pmap, old_map->pmap, |
| 1938 | new_entry->start, |
| 1939 | (old_entry->end - old_entry->start), |
| 1940 | old_entry->start); |
| 1941 | break; |
| 1942 | |
| 1943 | case VM_INHERIT_COPY: |
| 1944 | /* |
| 1945 | * Clone the entry and link into the map. |
| 1946 | */ |
| 1947 | |
| 1948 | new_entry = vm_map_entry_create(new_map); |
| 1949 | *new_entry = *old_entry; |
| 1950 | new_entry->wired_count = 0; |
| 1951 | new_entry->object.vm_object = VM_OBJECT_NULL; |
| 1952 | new_entry->is_a_map = FALSE; |
| 1953 | vm_map_entry_link(new_map, new_map->header.prev, |
| 1954 | new_entry); |
| 1955 | if (old_entry->is_a_map) { |
| 1956 | int check; |
| 1957 | |
| 1958 | check = vm_map_copy(new_map, |
| 1959 | old_entry->object.share_map, |
| 1960 | new_entry->start, |
| 1961 | (vm_size_t)(new_entry->end - |
| 1962 | new_entry->start), |
| 1963 | old_entry->offset, |
| 1964 | FALSE, FALSE); |
| 1965 | if (check != KERN_SUCCESS) |
| 1966 | printf("vm_map_fork: copy in share_map region failed\n"); |
| 1967 | } |
| 1968 | else { |
| 1969 | vm_map_copy_entry(old_map, new_map, old_entry, |
| 1970 | new_entry); |
| 1971 | } |
| 1972 | break; |
| 1973 | } |
| 1974 | old_entry = old_entry->next; |
| 1975 | } |
| 1976 | |
| 1977 | new_map->size = old_map->size; |
| 1978 | vm_map_unlock(old_map); |
| 1979 | |
| 1980 | return(new_map); |
| 1981 | } |
| 1982 | |
| 1983 | /* |
| 1984 | * vm_map_lookup: |
| 1985 | * |
| 1986 | * Finds the VM object, offset, and |
| 1987 | * protection for a given virtual address in the |
| 1988 | * specified map, assuming a page fault of the |
| 1989 | * type specified. |
| 1990 | * |
| 1991 | * Leaves the map in question locked for read; return |
| 1992 | * values are guaranteed until a vm_map_lookup_done |
| 1993 | * call is performed. Note that the map argument |
| 1994 | * is in/out; the returned map must be used in |
| 1995 | * the call to vm_map_lookup_done. |
| 1996 | * |
| 1997 | * A handle (out_entry) is returned for use in |
| 1998 | * vm_map_lookup_done, to make that fast. |
| 1999 | * |
| 2000 | * If a lookup is requested with "write protection" |
| 2001 | * specified, the map may be changed to perform virtual |
| 2002 | * copying operations, although the data referenced will |
| 2003 | * remain the same. |
| 2004 | */ |
| 2005 | vm_map_lookup(var_map, vaddr, fault_type, out_entry, |
| 2006 | object, offset, out_prot, wired, single_use) |
| 2007 | vm_map_t *var_map; /* IN/OUT */ |
| 2008 | register vm_offset_t vaddr; |
| 2009 | register vm_prot_t fault_type; |
| 2010 | |
| 2011 | vm_map_entry_t *out_entry; /* OUT */ |
| 2012 | vm_object_t *object; /* OUT */ |
| 2013 | vm_offset_t *offset; /* OUT */ |
| 2014 | vm_prot_t *out_prot; /* OUT */ |
| 2015 | boolean_t *wired; /* OUT */ |
| 2016 | boolean_t *single_use; /* OUT */ |
| 2017 | { |
| 2018 | vm_map_t share_map; |
| 2019 | vm_offset_t share_offset; |
| 2020 | register vm_map_entry_t entry; |
| 2021 | register vm_map_t map = *var_map; |
| 2022 | register vm_prot_t prot; |
| 2023 | register boolean_t su; |
| 2024 | |
| 2025 | RetryLookup: ; |
| 2026 | |
| 2027 | /* |
| 2028 | * Lookup the faulting address. |
| 2029 | */ |
| 2030 | |
| 2031 | vm_map_lock_read(map); |
| 2032 | |
| 2033 | #define RETURN(why) \ |
| 2034 | { \ |
| 2035 | vm_map_unlock_read(map); \ |
| 2036 | return(why); \ |
| 2037 | } |
| 2038 | |
| 2039 | /* |
| 2040 | * If the map has an interesting hint, try it before calling |
| 2041 | * full blown lookup routine. |
| 2042 | */ |
| 2043 | |
| 2044 | simple_lock(&map->hint_lock); |
| 2045 | entry = map->hint; |
| 2046 | simple_unlock(&map->hint_lock); |
| 2047 | |
| 2048 | *out_entry = entry; |
| 2049 | |
| 2050 | if ((entry == &map->header) || |
| 2051 | (vaddr < entry->start) || (vaddr >= entry->end)) { |
| 2052 | vm_map_entry_t tmp_entry; |
| 2053 | |
| 2054 | /* |
| 2055 | * Entry was either not a valid hint, or the vaddr |
| 2056 | * was not contained in the entry, so do a full lookup. |
| 2057 | */ |
| 2058 | if (!vm_map_lookup_entry(map, vaddr, &tmp_entry)) |
| 2059 | RETURN(KERN_INVALID_ADDRESS); |
| 2060 | |
| 2061 | entry = tmp_entry; |
| 2062 | *out_entry = entry; |
| 2063 | } |
| 2064 | |
| 2065 | /* |
| 2066 | * Handle submaps. |
| 2067 | */ |
| 2068 | |
| 2069 | if (entry->is_sub_map) { |
| 2070 | vm_map_t old_map = map; |
| 2071 | |
| 2072 | *var_map = map = entry->object.sub_map; |
| 2073 | vm_map_unlock_read(old_map); |
| 2074 | goto RetryLookup; |
| 2075 | } |
| 2076 | |
| 2077 | /* |
| 2078 | * Check whether this task is allowed to have |
| 2079 | * this page. |
| 2080 | */ |
| 2081 | |
| 2082 | prot = entry->protection; |
| 2083 | if ((fault_type & (prot)) != fault_type) |
| 2084 | RETURN(KERN_PROTECTION_FAILURE); |
| 2085 | |
| 2086 | /* |
| 2087 | * If this page is not pageable, we have to get |
| 2088 | * it for all possible accesses. |
| 2089 | */ |
| 2090 | |
| 2091 | if (*wired = (entry->wired_count != 0)) |
| 2092 | prot = fault_type = entry->protection; |
| 2093 | |
| 2094 | /* |
| 2095 | * If we don't already have a VM object, track |
| 2096 | * it down. |
| 2097 | */ |
| 2098 | |
| 2099 | if (su = !entry->is_a_map) { |
| 2100 | share_map = map; |
| 2101 | share_offset = vaddr; |
| 2102 | } |
| 2103 | else { |
| 2104 | vm_map_entry_t share_entry; |
| 2105 | |
| 2106 | /* |
| 2107 | * Compute the sharing map, and offset into it. |
| 2108 | */ |
| 2109 | |
| 2110 | share_map = entry->object.share_map; |
| 2111 | share_offset = (vaddr - entry->start) + entry->offset; |
| 2112 | |
| 2113 | /* |
| 2114 | * Look for the backing store object and offset |
| 2115 | */ |
| 2116 | |
| 2117 | vm_map_lock_read(share_map); |
| 2118 | |
| 2119 | if (!vm_map_lookup_entry(share_map, share_offset, |
| 2120 | &share_entry)) { |
| 2121 | vm_map_unlock_read(share_map); |
| 2122 | RETURN(KERN_INVALID_ADDRESS); |
| 2123 | } |
| 2124 | entry = share_entry; |
| 2125 | } |
| 2126 | |
| 2127 | /* |
| 2128 | * If the entry was copy-on-write, we either ... |
| 2129 | */ |
| 2130 | |
| 2131 | if (entry->needs_copy) { |
| 2132 | /* |
| 2133 | * If we want to write the page, we may as well |
| 2134 | * handle that now since we've got the sharing |
| 2135 | * map locked. |
| 2136 | * |
| 2137 | * If we don't need to write the page, we just |
| 2138 | * demote the permissions allowed. |
| 2139 | */ |
| 2140 | |
| 2141 | if (fault_type & VM_PROT_WRITE) { |
| 2142 | /* |
| 2143 | * Make a new object, and place it in the |
| 2144 | * object chain. Note that no new references |
| 2145 | * have appeared -- one just moved from the |
| 2146 | * share map to the new object. |
| 2147 | */ |
| 2148 | |
| 2149 | if (lock_read_to_write(&share_map->lock)) { |
| 2150 | if (share_map != map) |
| 2151 | vm_map_unlock_read(map); |
| 2152 | goto RetryLookup; |
| 2153 | } |
| 2154 | |
| 2155 | vm_object_shadow( |
| 2156 | &entry->object.vm_object, |
| 2157 | &entry->offset, |
| 2158 | (vm_size_t) (entry->end - entry->start)); |
| 2159 | |
| 2160 | entry->needs_copy = FALSE; |
| 2161 | |
| 2162 | lock_write_to_read(&share_map->lock); |
| 2163 | } |
| 2164 | else { |
| 2165 | /* |
| 2166 | * We're attempting to read a copy-on-write |
| 2167 | * page -- don't allow writes. |
| 2168 | */ |
| 2169 | |
| 2170 | prot &= (~VM_PROT_WRITE); |
| 2171 | } |
| 2172 | } |
| 2173 | |
| 2174 | /* |
| 2175 | * Create an object if necessary. |
| 2176 | */ |
| 2177 | if (entry->object.vm_object == VM_OBJECT_NULL) { |
| 2178 | |
| 2179 | if (lock_read_to_write(&share_map->lock)) { |
| 2180 | if (share_map != map) |
| 2181 | vm_map_unlock_read(map); |
| 2182 | goto RetryLookup; |
| 2183 | } |
| 2184 | |
| 2185 | entry->object.vm_object = vm_object_allocate( |
| 2186 | (vm_size_t)(entry->end - entry->start)); |
| 2187 | entry->offset = 0; |
| 2188 | lock_write_to_read(&share_map->lock); |
| 2189 | } |
| 2190 | |
| 2191 | /* |
| 2192 | * Return the object/offset from this entry. If the entry |
| 2193 | * was copy-on-write or empty, it has been fixed up. |
| 2194 | */ |
| 2195 | |
| 2196 | *offset = (share_offset - entry->start) + entry->offset; |
| 2197 | *object = entry->object.vm_object; |
| 2198 | |
| 2199 | /* |
| 2200 | * Return whether this is the only map sharing this data. |
| 2201 | */ |
| 2202 | |
| 2203 | if (!su) { |
| 2204 | simple_lock(&share_map->ref_lock); |
| 2205 | su = (share_map->ref_count == 1); |
| 2206 | simple_unlock(&share_map->ref_lock); |
| 2207 | } |
| 2208 | |
| 2209 | *out_prot = prot; |
| 2210 | *single_use = su; |
| 2211 | |
| 2212 | return(KERN_SUCCESS); |
| 2213 | |
| 2214 | #undef RETURN |
| 2215 | } |
| 2216 | |
| 2217 | /* |
| 2218 | * vm_map_lookup_done: |
| 2219 | * |
| 2220 | * Releases locks acquired by a vm_map_lookup |
| 2221 | * (according to the handle returned by that lookup). |
| 2222 | */ |
| 2223 | |
| 2224 | void vm_map_lookup_done(map, entry) |
| 2225 | register vm_map_t map; |
| 2226 | vm_map_entry_t entry; |
| 2227 | { |
| 2228 | /* |
| 2229 | * If this entry references a map, unlock it first. |
| 2230 | */ |
| 2231 | |
| 2232 | if (entry->is_a_map) |
| 2233 | vm_map_unlock_read(entry->object.share_map); |
| 2234 | |
| 2235 | /* |
| 2236 | * Unlock the main-level map |
| 2237 | */ |
| 2238 | |
| 2239 | vm_map_unlock_read(map); |
| 2240 | } |
| 2241 | |
| 2242 | /* |
| 2243 | * Routine: vm_map_simplify |
| 2244 | * Purpose: |
| 2245 | * Attempt to simplify the map representation in |
| 2246 | * the vicinity of the given starting address. |
| 2247 | * Note: |
| 2248 | * This routine is intended primarily to keep the |
| 2249 | * kernel maps more compact -- they generally don't |
| 2250 | * benefit from the "expand a map entry" technology |
| 2251 | * at allocation time because the adjacent entry |
| 2252 | * is often wired down. |
| 2253 | */ |
| 2254 | void vm_map_simplify(map, start) |
| 2255 | vm_map_t map; |
| 2256 | vm_offset_t start; |
| 2257 | { |
| 2258 | vm_map_entry_t this_entry; |
| 2259 | vm_map_entry_t prev_entry; |
| 2260 | |
| 2261 | vm_map_lock(map); |
| 2262 | if ( |
| 2263 | (vm_map_lookup_entry(map, start, &this_entry)) && |
| 2264 | ((prev_entry = this_entry->prev) != &map->header) && |
| 2265 | |
| 2266 | (prev_entry->end == start) && |
| 2267 | (map->is_main_map) && |
| 2268 | |
| 2269 | (prev_entry->is_a_map == FALSE) && |
| 2270 | (prev_entry->is_sub_map == FALSE) && |
| 2271 | |
| 2272 | (this_entry->is_a_map == FALSE) && |
| 2273 | (this_entry->is_sub_map == FALSE) && |
| 2274 | |
| 2275 | (prev_entry->inheritance == this_entry->inheritance) && |
| 2276 | (prev_entry->protection == this_entry->protection) && |
| 2277 | (prev_entry->max_protection == this_entry->max_protection) && |
| 2278 | (prev_entry->wired_count == this_entry->wired_count) && |
| 2279 | |
| 2280 | (prev_entry->copy_on_write == this_entry->copy_on_write) && |
| 2281 | (prev_entry->needs_copy == this_entry->needs_copy) && |
| 2282 | |
| 2283 | (prev_entry->object.vm_object == this_entry->object.vm_object) && |
| 2284 | ((prev_entry->offset + (prev_entry->end - prev_entry->start)) |
| 2285 | == this_entry->offset) |
| 2286 | ) { |
| 2287 | if (map->first_free == this_entry) |
| 2288 | map->first_free = prev_entry; |
| 2289 | |
| 2290 | SAVE_HINT(map, prev_entry); |
| 2291 | vm_map_entry_unlink(map, this_entry); |
| 2292 | prev_entry->end = this_entry->end; |
| 2293 | vm_object_deallocate(this_entry->object.vm_object); |
| 2294 | vm_map_entry_dispose(map, this_entry); |
| 2295 | } |
| 2296 | vm_map_unlock(map); |
| 2297 | } |
| 2298 | |
| 2299 | /* |
| 2300 | * vm_map_print: [ debug ] |
| 2301 | */ |
| 2302 | void vm_map_print(map, full) |
| 2303 | register vm_map_t map; |
| 2304 | boolean_t full; |
| 2305 | { |
| 2306 | register vm_map_entry_t entry; |
| 2307 | extern int indent; |
| 2308 | |
| 2309 | iprintf("%s map 0x%x: pmap=0x%x,ref=%d,nentries=%d,version=%d\n", |
| 2310 | (map->is_main_map ? "Task" : "Share"), |
| 2311 | (int) map, (int) (map->pmap), map->ref_count, map->nentries, |
| 2312 | map->timestamp); |
| 2313 | |
| 2314 | if (!full && indent) |
| 2315 | return; |
| 2316 | |
| 2317 | indent += 2; |
| 2318 | for (entry = map->header.next; entry != &map->header; |
| 2319 | entry = entry->next) { |
| 2320 | iprintf("map entry 0x%x: start=0x%x, end=0x%x, ", |
| 2321 | (int) entry, (int) entry->start, (int) entry->end); |
| 2322 | if (map->is_main_map) { |
| 2323 | static char *inheritance_name[4] = |
| 2324 | { "share", "copy", "none", "donate_copy"}; |
| 2325 | printf("prot=%x/%x/%s, ", |
| 2326 | entry->protection, |
| 2327 | entry->max_protection, |
| 2328 | inheritance_name[entry->inheritance]); |
| 2329 | if (entry->wired_count != 0) |
| 2330 | printf("wired, "); |
| 2331 | } |
| 2332 | |
| 2333 | if (entry->is_a_map || entry->is_sub_map) { |
| 2334 | printf("share=0x%x, offset=0x%x\n", |
| 2335 | (int) entry->object.share_map, |
| 2336 | (int) entry->offset); |
| 2337 | if ((entry->prev == &map->header) || |
| 2338 | (!entry->prev->is_a_map) || |
| 2339 | (entry->prev->object.share_map != |
| 2340 | entry->object.share_map)) { |
| 2341 | indent += 2; |
| 2342 | vm_map_print(entry->object.share_map, full); |
| 2343 | indent -= 2; |
| 2344 | } |
| 2345 | |
| 2346 | } |
| 2347 | else { |
| 2348 | printf("object=0x%x, offset=0x%x", |
| 2349 | (int) entry->object.vm_object, |
| 2350 | (int) entry->offset); |
| 2351 | if (entry->copy_on_write) |
| 2352 | printf(", copy (%s)", |
| 2353 | entry->needs_copy ? "needed" : "done"); |
| 2354 | printf("\n"); |
| 2355 | |
| 2356 | if ((entry->prev == &map->header) || |
| 2357 | (entry->prev->is_a_map) || |
| 2358 | (entry->prev->object.vm_object != |
| 2359 | entry->object.vm_object)) { |
| 2360 | indent += 2; |
| 2361 | vm_object_print(entry->object.vm_object, full); |
| 2362 | indent -= 2; |
| 2363 | } |
| 2364 | } |
| 2365 | } |
| 2366 | indent -= 2; |
| 2367 | } |